Make pasta for the dumplings: Mix and knead egg, flour, some salt and enough water to form an elastic, not sticky dough.,Let rest for 1 hour.,Make filling:,Mix meat, onion slices and salt and pepper and knead with your hands (the juices released from the onions make the filling tasty and juicy).,Roll out dough, not too thin. Use a large round cookie cutter, glass or small bowl (about 3-4 inches diameter) to make rounds. Scraps can be rerolled.,Mount a spoon of filling in the center of each round. Dot each with a little butter. Fold two opposite sides up and pinch to seal. Pinch open ends to seal, then pull around and pinch ends to form a round dumpling. Spray steaming baskets with non-stick spray, place Manti, spacing apart so they don't touch, in baskets and steam for about 40 minutes. Pile Manti on platter, dotting with butter so they don't stick together. Serve with generous amount of sour cream.,,______